This invention relates to means for exhausting the working fluid medium of a turbine power plant particularly adapted to propel aircraft of the vertical take-off and landing (VTOL) class.
In VTOL aircraft the vertical lift, as for example in the Harrier aircraft, is obtained by directing the exhaust from the power plant in a vertical direction normal to the aircraft. In this instance the exhaust is diverted from its normal axial direction, in contrast to rotating the entire engine from a horizontal to a vertical position.
This invention is particularly directed to this type of aircraft configuration where the engine remains fixed and the exhaust gases developing the aircraft propelling force are routed to give the vertical and horizontal thrust. This invention contemplates utilizing a rotatable plug extending from the side walls of a two-dimensional nozzle and top and bottom aerodynamically continuous walls moveable to define certain nozzle configurations. Hence, in the take off regime for vertical lift, a valve or flow diverting means is opened exhausting the gases normal to the airplane's horizontal axis, while the plug is rotated in a closed position. When transitioning from the vertical to the normal (horizontal) flight condition, the plug and top and bottom walls are actuated so that they cooperate to form an efficacious vectoring nozzle while metering the exhaust in order to obtain a smooth transition while the heretofore opened valve is being actuated closed.
It is also contemplated that in the horizontal flight mode the top and bottom flaps control the nozzle throat area and the plug remains fixed in a given position.
Since the plug/nozzle configuration is operated in the hot gaseous stream, cooling means are contemplated and additionally the cooling structure is utilized to afford structural support.